1. Field of the Invention
Among other things, the present invention is related to an overlay for an implant or the combination of an implant and the overlay. The overlay is indentured and can interlock with the face of the implant. One or more fasteners secure the overlay to bone and the implant.
2. Description of the Previous Art
1) US Publish Patent Application No. 2003/0125739 A1—Bagga, et al. discloses a bioactive spinal implant and method of manufacture. Among other things, it does not appear that the Bagga invention practices the use of posts, supports or ties.
2) U.S. Pat. No. 6,767,367 B1—Michelson enables a spinal fusion implant having deployable bone engaging projections. Michelson teaches that the '367 implant 300 has a rotatable member 320 that is preferably frustoconical in shape. Rotatable member 320 has bone engaging projections 332 adapted to penetrably engage the bone of the adjacent vertebral bodies. Bone engaging projections 332 are preferably configured such that in a retracted position, implant 300 may be linearly inserted into the disc space. After implant 300 is inserted into the disc space, bone engaging projections 332 are moved to a deployed position to penetrably engage the endplates of each adjacent vertebral body and prevent the expulsion of implant 300 from the disc space.
3) U.S. Pat. No. 6,537,320 B1—Michelson enables a self-broaching, rotable, push-in interbody spinal fusion implant and method for its deployment. Among other things, it does not appear that the Michelson invention practices the use of posts, supports or ties.
4) U.S. Pat. No. 5,609,635—Michelson enables a lordotic interbody spinal fusion implant. The Michelson Summary of the Invention teaches that the '635 modular implants are generally wedge-shaped that have upper and lower surfaces conforming to the contours of the vertebral endplates, which contours include but are not limited to being relatively flat or convex. Michelson states, “As the disc spaces in the lumbar spine are generally lordotic, said implants in the preferred embodiment would be taller anteriorly, that is at the implant's insertion end, and less tall posteriorly, that is at the implant's trailing end. To introduce an implant that is taller at its insertion end than the space available at the posterior aspect of the disc space, even when that disc space is optimally distracted, is problematic.”
5) U.S. Pat. No. 6,302,914 B1—Michelson enables a lordotic interbody spinal fusion implant. The '914 Patent is a continuation Patent of the U.S. Pat. No. 5,609,635—Michelson Patent.
6) U.S. Pat. No. 6,066,175—Henderson, et al. enables a fusion stabilization chamber. Mesh cage 41 sits between vertebral bodies 43 and 45. Intervertebral discs 46 and 47 flank the vertebral bodies. The spinal cord is indicated by reference numeral 53. Cage 41 fills the space previously occupied by another such disc. The cage includes barrel vaults 48 and 49, and has flanges 50 and 51 which help to anchor the cage on the vertebral bodies and provide means for attachment thereto. The Henderson flanges also prevent the cage from being inadvertently tapped into the spinal cord, and they also distribute the shear and bending moment and thus increase the stability of the device. The flanges also provide one or more additional holes to accommodate more screws for affixing the device to the vertebral bodies. Both the flanges and barrel vaults are preferably integral with the cage. The barrel vaults can be either threaded or non-threaded. The screws which are inserted through the barrel vaults are preferably of the locking type, so that they lock into the barrel vaults when fully inserted. The cage is preferably rectangular when viewed from the top or the bottom. The cage may be constructed such that the bottom (the side pointed towards the spinal cord) is solid and not made of mesh. The top of the cage could also be solid. A mesh structure is most necessary on the sides of the cage, where the cage abuts the vertebral bodies, so as to promote fusion between the bone chips or bone substitute material inside the cage and the adjacent vertebral bodies.
7) U.S. Pat. No. 5,766,252—Henry, et al. enables an interbody spinal prosthetic implant and method. Among other things, the Henry device practices threaded hole 38 and longitudinal struts 84.
8) U.S. Pat. No. 5,425,772—Brantigan enables a prosthetic implant for intervertibral spinal fusion. Among other things, the '772 device practices traverse teeth or serrations 19 where the teeth have sharp peaks 19a, slopping walls 19b and valleys 19c.
9) U.S. Pat. No. 5,147,402—Bohler, et al. enables an implant for ingrowth of osseous tissue. Among other things, Bohler does not appear to practice a generally wedge shaped cage.
10) U.S. Pat. No. 6,746,484—Liu, et al. enables a spinal implant. Among other things, the Liu disclosure teaches that tool 22 has a milling cutter 23, central cutting portion 24 and two non-cutting portions 31, 36 arranged at opposite ends of central cutting portion 24. Non-cutting portions 31, 36 have height h corresponding to the intersomatic space and permitting uniform, symmetrical cutting of a predetermined length through a central region of both vertebral plates 15, 16. The geometry of portions 24, 31, 36 is determined for preparing the intersomatic space with the geometry of implant 1 to restore the natural lordosis of the intervertebral space, and correspondingly the distances represented by h and d1 are approximately equal.
11) U.S. Pat. No. 6,231,610 B1—Geisler enables an anterior cervical column support device. The '610 apparatus utilizes serrations on the load bearing surfaces and two screw holes.
12) U.S. Pat. No. 6,660,038 B2—Boyer, et al. enables skeletal reconstruction cages. The Boyer Patent discloses an end cap 210 suitable for coupling to central shaft 160 includes an outer wall 212, as well as a central hole disposed along axis 213 with a lower inner wall 214, an upper inner wall 216, and an inner ridge portion 218. Lower inner wall 214 extends about a depth H2 and is sized to fit snugly on an upper or lower portion 182, 184 of central shaft 160 with an upper or lower face 162, 164 abutting a shoulder 218. Preferably, upper inner wall 216 has a dimension that is about the same as dimension D5 of hole 178 of central shaft 160. End cap 210 is symmetrical about line 220, and is generally oblong in shape with first and second widths W2, W3. Notably, while outer wall 176 of central shaft 160 is generally circular, outer wall 212 of end cap 210 is generally oblong, so that a generally I-shaped skeletal reconstruction cage may be formed when a pair of end caps 210 are placed on central shaft 160.
13) U.S. Pat. No. 6,491,724—Ferree enables a spinal fusion cage with lordosis correction. Among other things, the '724 Patent teaches, “In the preferred embodiment, the anterior portion 112 includes mating members 120 and 122 with teeth 124 or other features to form a locking or ratchet mechanism, as shown. Whatever apparatus is used, the purpose is to maintain the height of the anterior portion of the cage at a desired level consistent with lordosis upon installation.”
14) U.S. Pat. No. 6,117,174—Nolan enables a spinal implant device. Among other things, the '174 apparatus utilizes disc 14 made of the same material as body 12. Inner surfaces of legs 18 and 20 are curved.
15) US Published Patent Application No. 20070016295—Boyd discloses a reinforced molded implant formed of cortical bone. Boyd reads, “Implant 10 defines a longitudinal axis 11 and includes a first strut 12, a second strut 14 spaced from first strut 12, and cross-member 16 extending therebetween. First strut 12 and second strut 14 are each positioned to lie in a plane substantially parallel to longitudinal axis 11. Implant 10 includes at least one additional cross-member 16 A connecting first strut 12 and second strut 14. It is understood that in alternative embodiments implant 10 can have one or a plurality of cross-members connecting first strut 12 to second strut 14.”
16) U.S. Pat. No. 6,090,143—Meriwether, et al. enables a box cage for intervertebral body fusion. Meriwether reads, “FIG. 6 illustrates a further embodiment of the invention which is a slight modification of that shown in FIG. 4. In the embodiment of FIG. 6, rather than having a rectangular longitudinal cross-section, it is trapezoidal such that the resulting cage member, indicated generally by numeral 110, is wedge-shaped. The assembled cage comprises a box-like base 112 and a cover 114 dimensioned to fit over the base much like the cover on a shirt box. The height dimension of the rightmost ends of the base and cover are greater than the height dimension of the corresponding, opposed left side ends, thus providing the desired wedge shape. Upwardly projecting ribs 116 and 118 extend along the rear and front side edges, respectfully, and likewise, the base 112 includes longitudinally extending ribs 120 and 122 projecting downwardly from the undersurface of the base along the side edges thereof. The right and left ends of the base 112 and the cover 114 include semi-circular cut-outs as at 124 and 126 and 128-130 such that when the cover 114 is placed upon the base 112, circular apertures are formed. These apertures are adapted to receive a tapered screw 132 therein. The slope of the taper of the screw is designed to correspond to that of the cage assembly 110 such that when the screw 132 is threaded into the circular opening defined by arcuate cut-outs 124 and 126 and advanced by turning until the leading end 134 of the screw enters the circular aperture 128-130, further turning of the screw will raise the case cover 114 relative to its base 112, allowing adjustment of the cage height following positioning thereof between adjacent vertebral bodies.”
17) U.S. Pat. No. 6,159,245—Meriwether, et al. enables a box cage for intervertebral body fusion. The '143 Meriwether Patent is a continuation of U.S. Pat. No. 6,090,143-Meriwether, et al.
18) U.S. Pat. No. 6,432,107—Ferree enables enhanced surface area spinal fusion devices. The '107 Patent teaches, “The device 200 fits into slots 204 and 206 made in upper and lower vertebrae 208 and 210, respectively, allowing the lower section to fuse within the body of the lower vertebrae 210, and the upper section to fuse within the body of the upper vertebrae 208. Thus, in contrast to existing devices, the device 200 and the alternative embodiments disclosed herein feature considerably more intimate contact with cancellous bone due to the fact that the device is inserted directly into the cavities 204 and 206. Rather than a relatively minor amount of scraping of the end plates of the vertebrae to be distracted, the entire end portions of the device 200 which penetrate the upper and lower vertebrae make contact with cancellous bone, thereby enhancing fusion considerably. FIG. 2B is a cross-section of a vertebrae of FIG. 2A as viewed from a top-down perspective, showing how the device fits tightly along the entire walls of the channels created in the vertebrae.” Among other things, the Ferree device does not allow the surgeon to see through the device after insertion into the surgical cavity.
19) U.S. Pat. No. 6,569,201—Moumene, et al. enables a hybrid composite interbody fusion device. The '201 Patent reads, “ . . . there is provided a non-resorbable support 1 having an upper contact surface 3, and a lower contact surface 5, these surfaces being connected by side surfaces 7, 9, each side surface forming a portion of the outer surface 11. Osteoconductive pore 2 passes completely through the support 1 from lower surface 5 to upper contact surface 3, and opens onto upper and lower openings 15, 17 formed in the upper 3 and lower 5 contact surfaces. Osteoconductive pore 2 forms a void 23 within the support and defines an inner surface 13, and opens onto side surface openings 19, 21 formed in side surfaces 7, 9. Void section 23 is suitable for housing a bone growth material such as bone chips (not shown). In this case, the non-resorbable support 1 has a cage shape.” Among other things, Moumene does not teach a span of receptacles.